target-arm: Store AIF bits in env->pstate for AArch32

To avoid complication in code that otherwise would not need to
care about whether EL1 is AArch32 or AArch64, we should store
the interrupt mask bits (CPSR.AIF in AArch32 and PSTATE.DAIF
in AArch64) in one place consistently regardless of EL1's mode.
Since AArch64 has an extra enable bit (D for debug exceptions)
which isn't visible in AArch32, this means we need to keep
the enables in env->pstate. (This is also consistent with the
general approach we're taking that we handle 32 bit CPUs as
being like AArch64/ARMv8 CPUs but which only run in 32 bit mode.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

1 files changed, 17 insertions, 12 deletions

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 61303b6ce9..01d1ef6679 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -2475,7 +2475,7 @@ uint32_t cpsr_read(CPUARMState *env)
         (env->CF << 29) | ((env->VF & 0x80000000) >> 3) | (env->QF << 27)
         | (env->thumb << 5) | ((env->condexec_bits & 3) << 25)
         | ((env->condexec_bits & 0xfc) << 8)
-        | (env->GE << 16);
+        | (env->GE << 16) | env->daif;
 }
 
 void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
@@ -2502,6 +2502,9 @@ void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
         env->GE = (val >> 16) & 0xf;
     }
 
+    env->daif &= ~(CPSR_AIF & mask);
+    env->daif |= val & CPSR_AIF & mask;
+
     if ((env->uncached_cpsr ^ val) & mask & CPSR_M) {
         if (bad_mode_switch(env, val & CPSR_M)) {
             /* Attempt to switch to an invalid mode: this is UNPREDICTABLE.
@@ -2963,7 +2966,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
     env->condexec_bits = 0;
     /* Switch to the new mode, and to the correct instruction set.  */
     env->uncached_cpsr = (env->uncached_cpsr & ~CPSR_M) | new_mode;
-    env->uncached_cpsr |= mask;
+    env->daif |= mask;
     /* this is a lie, as the was no c1_sys on V4T/V5, but who cares
      * and we should just guard the thumb mode on V4 */
     if (arm_feature(env, ARM_FEATURE_V4T)) {
@@ -3636,12 +3639,12 @@ uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
     case 9: /* PSP */
         return env->v7m.current_sp ? env->regs[13] : env->v7m.other_sp;
     case 16: /* PRIMASK */
-        return (env->uncached_cpsr & CPSR_I) != 0;
+        return (env->daif & PSTATE_I) != 0;
     case 17: /* BASEPRI */
     case 18: /* BASEPRI_MAX */
         return env->v7m.basepri;
     case 19: /* FAULTMASK */
-        return (env->uncached_cpsr & CPSR_F) != 0;
+        return (env->daif & PSTATE_F) != 0;
     case 20: /* CONTROL */
         return env->v7m.control;
     default:
@@ -3688,10 +3691,11 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t reg, uint32_t val)
             env->v7m.other_sp = val;
         break;
     case 16: /* PRIMASK */
-        if (val & 1)
-            env->uncached_cpsr |= CPSR_I;
-        else
-            env->uncached_cpsr &= ~CPSR_I;
+        if (val & 1) {
+            env->daif |= PSTATE_I;
+        } else {
+            env->daif &= ~PSTATE_I;
+        }
         break;
     case 17: /* BASEPRI */
         env->v7m.basepri = val & 0xff;
@@ -3702,10 +3706,11 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t reg, uint32_t val)
             env->v7m.basepri = val;
         break;
     case 19: /* FAULTMASK */
-        if (val & 1)
-            env->uncached_cpsr |= CPSR_F;
-        else
-            env->uncached_cpsr &= ~CPSR_F;
+        if (val & 1) {
+            env->daif |= PSTATE_F;
+        } else {
+            env->daif &= ~PSTATE_F;
+        }
         break;
     case 20: /* CONTROL */
         env->v7m.control = val & 3;